Elevator door



ELEVATOR DOOR C. WOODRUFF Filed Feb. 27, 1929 July 11, 1933.

INVENTOR. ODR up F.

'A TTORNE YS.

CARL W0 Patented July 11, 1933 oN TEo STATES PATENT OFFICE CARL woonnurr, orsAn' FRANCISCO, oALIronnIA ELEVATOBI DOOR Application filed February 27,1928. Serial No. 343,080.

This invention relates to elevator doors,-

particularly as used on the building .to close the opening to the shaft, and the objects of the invention are to provide improvements in the construction of such doors whereby they are more effectively operated, utmost safety is assured, fire hazard reduced,'the construction is simplified, and minimum space is required for their installation.

Briefly described my invention comprises a pair of sliding or rather rolling elevator doors, and operating mechamsm therefor, with the doors suspended from above on a common track, and with one of the doors the doors of Fig. 1 as seen from the line.

22 thereof.

Fig. 3 is an enlarged cross section of-the automatic brake which stops the shaft of the door-opening motor. a

In the drawing the door-way or opening is indicated at 1, the wall of the elevator shaft at 2., the slotted or hollow door 3, door which rolls into the slotted door is indicated at 4, and the common track from which the doors are suspended is indicated at secured to the wall of the elevator shaft.

The doors to operate in accordance with my invention may be of any desired con struction such as grille work, glass panels, or otherwise, but in the present embodiment I show the doors as made of sheet metal panels. The hollow door 3 is formed with spaced walls as indicated and is closed at the rearward edge at 3, and open at the opposite edge to receive the other door 4. Door 4 is in this particular case also shown hollow with sheet metal walls and of a total thickness to pass easily within the hollowdoor 3 while at the same time provide sufiic-ient space between thetwo doors for vertically extending angle iron braces as indicatedat 5 5, also the slotted openingin door 3. is preferablyreinforcedeitherby angle irons or turning the edges of the side walls inward as indicated.

Hollow door by means of hangers .7 carrying rollers 8, and the forward edgeof 'do0r'4 islikewis'e suspended from the same track by means of a hanger 9 carrying roller 10 rolling on the same track-as indicated, while the rearward portion of the inner door 4 is rollably carried on the hollow door 3 itself by means of rollers as indicated at 11 carried by an up wardly extending flange 12 of door 4 and which rollers 11 roll on apair of inwardly extending tracks 13 carried by andsecured to and wltlnn door 3 asindicated best in Fig. 2 of the ClIZLWIH 1 The upwardly extending flange from door 4 acts-as an aligning guide for the same between the tracks 13 so as to preserve the clearance, of the doors when one is slid with in the other. Q

The lower endsof the doors a eguided means of rollers or blocks travelling in a 30 groove 14 formedin a suitable floor guide15. The guide block on the door 3 is indicated at 16 extending from the closed bottom edge of the door, while the guide block on'the door 4 is indicated at 17 also extending from the closed door edge of door 4, and which block 17 slides into a recess 18 out out of the closed edge of door 3 when both doors are fully opened. The rearward lower edge of door 4 is slidably aligned within door 3 through the provision of a pair of inwardlyturned shoulders 19 or other guides within door3 as indicated best in Fig. 2.' r In order to actuate the doors asdescribed a short horizontalrackQO is secured to and '5 carried by the bracket 7 of door 3, and which rack is engaged by a pinion 21' secured to a shaft 22 rotatably mounted in a fixedbracket 23 secured to the wall, and which shaft 22 i also carries a worm wheel 24 engaged by a 3 is suspended from track 5 worm secured on a shaft 26 extending to a driving motor 27 mounted on the wall or fixed portion of the building. Motor 27 is a reversing motor so that the worm shaft may be actuated in either direction to open or close the doors as may be desired.

A second rack is provided as shown at 28 secured to the underside of track 5 with its teeth projecting downwardly and engaged by a pinion 29 secured to a shaft 30 rotatably carried by door 4 as indicated and which shaft 30 has an additional pinion 31 secured thereto and rolling in mesh with a third rack 33 secured to or formed on the upper edge of the flange 12 which projects upwardly from the inner door 4.

' By the arrangement described when the wormshaft 26 'is revolved to open door 3 or that is roll it to the left the action of the pinions and racks described will cause door 4 to roll at higher speed in the same direction into the door 3, and the motions of the doors will be reversed upon reversing of shaft 26.

The electric motor is energized for opening the doors by a circuit 34, and for closing the doors by a circuit 35 by means of a double switch 36 mounted within the elevator and operated by its attendant, it being understood that suitable circuit contacts are made When the elevator arrives at each floor so as to'permit of controlling the circuit by means of this switch, but such sliding contacts being old in elevator construction are not shown in thedrawing as they would but tend to confuse with the necessary features of the disclosure.

Assuming therefore that when circuit 34 is closed by the switch the doors will be opened by the direction of rotation of the motor, and that when circuit 35 is closed by opposite throw of the switch the doors will be closed, it follows that some automatic provision should be made so that the motor will be thrown out of c-ircuitjust before the doors have reached their final 'positioneither way. To disconnect the motor atopposite points of rolling of the doors I provide a switch for each circuit'as'shown at 37 and 38 which switchesmay be considered as spring actuated switches normallyheld closed and which are positively opened by a projection as at 37 38 on thedoors when they have rolled to a predetermined position, just prior to the entirely opened or entirely closed position, so that the opening or closing circuit will be automatically broken at a predetermined point irrespective of the operators switch 36 being closed. 7

Since the motor shaft would tend to revolve quite a number of turns after breaking the circuit due to the momentum of the armature I provide a brake wheel 39 on the motorshaft normally clamped by a spring actuated brake 40 to hold the shaft from revolving, and which brake is released by a magnet 41 on a circuit in series with the motor, so that upon energizing the mot-or in either direction the energizing current will at oncerelease the brake 40 to permit revolution of the worm shaft and consequent movement of the doors, and when the circuit is broken the brake will instantly clamp the brake wheel 39 and stop the shaft.

In operation of the doors it will be seen from what has been said that when the elevator comes to the desired floor and the opening circuit 34 is closed by the operator moving theswitch 36, the doors at once roll open and the forward door 4 rollsinto the rearward or hollow door 3. Then the doors reach a predetermined point switch 37 tripped to brake the circuit, and instantly the worm shaft is stopped by the automatic clamping action of brake 40. hen it is desired to close the doors the reverse action of switch 36 energizes the reversing circuit 35 and the doors at once roll to closed position, to trip switch 38 to brake the clos ing circuit and consequently clamp the worm shaft by means of brake 40 as described. It being understood that magnet 41 is in series with both the opening and the closing circuits so that whichever one is active will also actuate the magnet to draw upward and release the brake 40.

Having thus described my invention it v will be seen that "arious modifications may be made both in the structure of the doors and the precise methodof operating them, and any such as fall within the spirit of the invention are intended to be included in the appended claims.

I'claim:

1. A pair of rolling doors arranged to jointly cover and uncover a doorway, one of said doors being slotted, and the other or inner of said doors arranged to roll into the slot, track means above the doors supporting them for rollable movement, and means for rolling the doors to open and close including gear mechanism with gears of dif ferent diameters whereby the last mentioned door will move faster than the slotted door in opening and closing the doorway, said mechanism positioned above the doors.

2. In a structure-as specified in claim 1, said mechanism including a rack carried by the upper end of the inner door, a vertically positioned pinion revolvably carried on the upper end of the slotted door engaging said rack, a second pinion connected for rotation with the first pinion and in opposed relation thereto, and a rack fixed to the building engaged. by the second pinion.

CARL woonnurr. 

